The term "multimedia" as used herein refers to computer programs that combine audio and visual components in a single work. These components can be in the form of videos that run in a window on the computer display screen, animations, still images and other graphic images (photographic or computer generated), Red Book audio (sound in conventional music CD format), wave files (digitized sound), and/or MIDI files, which are used to produce music or other sounds by controlling a sound board in the computer, external music synthesizer, or other hardware. Multimedia components can be combined in unlimited ways by an author to create many different types of works; such works are typically intended for informational, educational, and/or entertainment purposes.
Because a single multimedia work often includes hundreds of megabytes of data, the current most popular storage and distribution medium for such works is the CD-ROM. Typically, once a multimedia work is finalized, a master CD-ROM is "burned" on which the entire work is stored. Subsequently, the master CD-ROM is used to produce the CD-ROMs actually distributed to end users who lease the multimedia work for play. Currently, the CD-ROM technology does not normally permit changes to be made to the CD-ROMs that will be distributed. A CD-ROM is essentially a write once, read many times storage medium. Thus, it is generally not possible to make changes in or additions to a multimedia work stored on a conventional CD-ROM. Furthermore, it is unusual for changes or additions to a computer program to be easily made without recompiling the program or changing the source code, if the code is in a language that is normally executed by an interpreter. For these reasons, changes or additions to a multimedia work recorded on a CD-ROM normally require that the disk be replaced with a new one on which the revised or added content is included.
While the cost of a replacement CD-ROM is only a few cents to a software publisher, it is likely that if the changes or additions to a multimedia work could be made with files of one to two megabytes or less in size, the changes could be distributed to end users on floppy disks, or downloaded via a modem. Using such files, a user could easily update the multimedia work. Updating a work in this manner would be both more convenient and would enable a limited segment of the total audience to customize a title, thereby providing enhanced convenience. However, current techniques and authoring programs for producing files that are executed to play a multimedia work do not provide for repurposing the work with subsequently added external files. Although the term "hard wired" is most often used in connection with hardware components, it is also applicable to the prior art systems conventionally used for creating and playing multimedia works, in that such systems and techniques do not permit changes in a multimedia work at run time. While it is true that multimedia works written with the intent of accessing a plurality of add-on files, for example, by selecting a file from a menu, can change when they play, these changes must be "hard wired" in the work when it is stored on the CD-ROM. For example, Microsoft Corporation's "Golf for Windows" is distributed on a CD-ROM and was specifically written to include a provision for enabling the game to be played on a golf course selected from a list of available courses stored on the user's hard drive, which are sold as accessories or add-ons to the basic game. However, multimedia works that are not written with the facilities for selecting and using added files cannot generally be subsequently modified to enable such changes or additions. Furthermore, even such multimedia works as Golf for Windows can only be adapted in the manner specifically contemplated at the time the work was compiled and stored on the CD-ROM. The game cannot be modified during play, for example, to insert a "Caddy" that offers advice on the club that should be chosen for hitting the golf ball in a particular situation.
As used throughout this specification and in the claims that follow, the term "repurposing a multimedia work" means modification of the work after it is stored on a non-volatile storage medium (e.g., a CD-ROM) in a manner that was not specifically provided for in the work when created. Repurposing a multimedia work is thus substantially different than providing for specific add-on features at the time the work was created.
There are numerous instances where, following the release and commercial success of a multimedia work, it becomes evident that there is a market for more features or functions. For instance, in an educational multimedia work, the users may request that additional information be provided about certain topics in the multimedia work. Thus, a multimedia work dealing with Introductory Biology might be expanded by adding more detailed modules related to specific topics, such as the "Reproductive Systems Of Mammals" that are only generally covered in the multimedia work. The modules might be distributed on additional CD-ROM disks, a tape, or on floppy disks, depending upon the size of the module. By integrating such modules into the original multimedia work, much of the programming effort in the work that is devoted to presenting the topic could be used in connection with the modules, and duplication of content could be avoided. In addition, the integration of follow-up modules to repurpose the original multimedia work would provide a more seamless presentation of the subject. The system and/or method that enables such repurposing should be relatively broad in its ability to integrate changes and additions to a multimedia work. The ability to repurpose a work in this manner should also provide a considerable advantage in revising works to correct errors or improve the quality of the work.